We report the ion measurement of time-of-flight with Faraday cup and the ion energy with a simple analytic model involving an isothermal rarefaction. The targets were polished glass coated with 100A to 1μm of Al and Au foils. Irradiance was varied in the range 1012 to 1014 W/cm2 with constant laser power and variable focal size. Deductions include the scaling relationship of ion velocity at λ = 1.06μm with different focal size, and the anisotropic distributions have been clearly observed.